In communication systems, the technique used to prevent unuseful traffic to use communication system resources is filtering. On large local area networks, a significant part of the traffic is a repetitive or informative traffic intended for all stations, known as broadcast traffic. This type of traffic is used to locate, update or give information about network resources. For example, a station connected to a network sends broadcast frames in order to obtain the physical address of a station connected to a different network. Generally this broadcast frame is sent several times to be sure that it will be received. Most of this broadcast traffic is unuseful and can be filtered and discarded to increase efficient data throughput, provided some means ensure that its functionality is fulfilled.
The typical problems in the prior art solutions are generally that the broadcast frames are held until a media becomes available. This solution does not balance the traffic and may cause some connection lost when bridging to a media of a low speed.
In other known systems, filtering is static which means that a table containing the types of broadcast frames not to be discarded, has to be maintained. This solution implies to stop the communication system when updating the table.
In the IBM.RTM. infrared wireless LAN, wherein mobile stations are connected to low speed infrared LAN, all the broadcast frames from high speed network are filtered until a mobile station sends a broadcast request.